Cooling Tower Composition for Zero Blowdown Operation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for reducing or eliminating cooling tower blowdown are either costly, impractical, or ineffective in preventing corrosion and deposition, leading to environmental impact and water conservation challenges.

Innovation Solution

A composition comprising an aqueous solution of softened water, 2-acrylamido-2-methylpropyl sulfonic acid (AMPS) acrylic terpolymer, sodium silicate, phosphate, and polyphosphate, along with a method involving softened water, bypass filtration, and the use of a biocide, to control corrosion and deposition within cooling towers, allowing for increased cycles and potential elimination of blowdown.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If cycles are increased to reduce blowdown, then water conservation is improved, but scale formation and corrosion increase

Engineering Contradiction:
Improveblowdown water lossVSAvoidscale formation and corrosion
Core Design Contradiction:
Loss of substanceVSObject-affected harmful factors

Solution Approach 1:

The invention changes the chemical parameters of the cooling water system by introducing a specific composition containing phosphates, polyphosphates, silicates, and other corrosion inhibitors. This composition modifies the water chemistry to prevent scale formation and corrosion even at high cycle concentrations (20:1 or higher), allowing the system to operate with minimal or no blowdown while maintaining system integrity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention uses chemical intermediaries (corrosion inhibitors and scale preventors in the composition) that act as mediators between the concentrated cooling water and the metal surfaces. These intermediaries form protective films on metal surfaces and prevent direct contact between aggressive concentrated water and equipment, enabling high-cycle operation without corrosion or scaling.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If conventional scale inhibitors are used to increase cycles, then blowdown is reduced, but the system is limited to maximum 150-200 times saturation

Engineering Contradiction:
Improveblowdown water lossVSAvoidcycle concentration limit
Core Design Contradiction:
Loss of substanceVSProductivity

Solution Approach 1:

The invention employs a composite chemical composition containing multiple active ingredients (phosphates, polyphosphates, silicates, carboxylic acids, and other corrosion inhibitors) that work synergistically. This composite approach provides superior scale inhibition and corrosion protection compared to single-ingredient treatments, enabling the system to operate at cycle concentrations exceeding 200:1, far beyond the limitations of conventional scale inhibitors.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If blowdown is eliminated to conserve water, then environmental impact is reduced, but corrosion and deposition control becomes difficult

Engineering Contradiction:
Improveenvironmental impactVSAvoidcorrosion and deposition control
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The invention applies preliminary protective action by introducing the corrosion inhibitor composition before scale formation and corrosion can occur. The composition proactively forms protective films on metal surfaces and prevents deposit formation, allowing the system to operate at high cycles with no blowdown while maintaining reliable corrosion and deposition control throughout operation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention ensures continuous protection against corrosion and deposition by maintaining the composition in the cooling water system at all times during high-cycle operation. The continuous presence of corrosion inhibitors and scale preventors provides ongoing protection, enabling the system to operate indefinitely at 20:1 or higher cycles with minimal or no blowdown while maintaining system reliability.

Inventive Principle:
Principle #20Continuity of useful action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively minimizes corrosion and deposition, enabling cooling towers to operate with minimal or no blowdown, conserving water and reducing environmental impact while maintaining system efficiency.

Implementation Method 1

a composition for controlling corrosion and deposition within a cooling tower

Methodology Applied
Scientific EffectCorrosion inhibition:

Implementation Method 2

a composition for controlling corrosion and deposition within a cooling tower

Methodology Applied
Scientific EffectDeposition control: Deposition (physical)

Implementation Method 3

an aqueous solution of softened water

Methodology Applied
Scientific EffectIon exchange: Ion Exchange

Data Source

PatentUS8128841B2Composition for operation of evaporative cooling towers with minimal or no blowdown
Publication Date: 2012.03.06 PROCHEMTECH INT

AI summary

A method and composition are provided for the operation of an evaporative cooling tower with minimal, or no, blowdown. In some embodiments, the method involves using sodium cation-exchanged softened water as makeup water for the cooling tower, providing a bypass filter for suspended solids removal from the cooling water, treating the cooling water with a composition for control of corrosion and deposition, and using an effective biocide for control of biological growth within the cooling tower system. In some embodiments, a composition is provided that comprises AMPS acrylic terpolymer, sodium silicate, phosphate ions, and polyphosphate ions. When dosed at the recommended levels, the composition controls corrosion of cooling system materials to generally acceptable levels in spite of the extremely corrosive environment resulting from the cycling of sodium cation-exchanged softened water in the cooling tower.